Reaction time measures are used in a recognition memory task to investigate the phenomenon that memory search rate decreases when human subjects are required to perform translation or recoding operations to match test items wwth rememmered target items. Two classes of theories are under invesigation, one of which claims that the phenomenon results from rehearsal strategies operating when target items are encoded, and the other of which claims that the phenomenon results from decoding operations taking place after the probe is precented. Other encoding and decoding processes are also being investigated with recognition reaction time measures, including processes whereby information is decoded from remembered sentential propositions and remembered visual images.